phone microsoft your problem may be OEM software sometimes microsoft will verify and talk you thro what next to validate your current copyI guess you have tried to do a full install of your upgrade copy that sometimes is the cure

When u try to download antispywarebeta it tells u 2 click continue to validate windows. After installing active x continue then install the windows genuine advantage validation tool then continue then continue then u should be taken back to the download site and your validation is complete. Try that. u dont have to download anything.

roll back to when all was ok and save the activation files then after you install the updates just reset the activation. The following is how to do it [taken from somewhere on here a while back] Keep your activation status intact when reinstalling XP

Have you ever wanted to reformat the hard disk and reinstall Windows XP on a system but you didn't want to mess around with Microsoft's Product Activation after the reinstall? Fortunately, you don't have to. As long as you aren't making any hardware alterations, you can back up the activation status files before you reformat the hard drive and then restore them after you reinstall the operating system. To perform the backup, follow these steps: 1. Use Windows Explorer to open the C:\Windows\System32 folder. 2. Copy the Wpa.dbl and Wpa.bak files to a floppy disk or CD.

To perform the restore, follow these steps: 1. Decline the activation request at the end of the installation procedure, and restart Windows XP. 2. During bootup, press [F8] to access the Windows Advanced Options menu. 3. Choose the Safe Mode (SAFEBOOT_OPTION=Minimal) option. 4. Use Windows Explorer to open the C:\Windows\System32 folder. 5. If they exist, rename the new Wpa.dbl and Wpa.bak files to Wpadbl.new and Wpabak.new. 6. Copy the original Wpa.dbl and Wpa.bak files from the floppy disk or CD to the C:\Windows\System32 folder. 7. Restart the system.